The High-Definition Multimedia Interface (HDMI) is a standard for transmitting digital television audiovisual signals from a DVD player, a set-top box or another audiovisual resource to a television set, a projector, a monitor or other video display apparatus. HDMI may support multi-channel audio data with high quality, and is applicable to numerous standards and high-definition (HD) electronic video formats. HDMI may also be used with respect to content protection technology. HDMI systems may allow the delivery of decompressed baseband digital-HD video and audio signals with little or no loss, and are readily linkable by means of a two-ply cable. HDMI systems may also be used to consolidate control operations between apparatuses, and can transfer content with high resolution.
While HDMI is adaptable to the standard for transferring a component video signal and a decompressed audio signal at the same time, it uses a transition-minimized differential signaling (TMDS) conversion scheme as a general transmission mode. Pursuant to this TMDS conversion scheme, parallel data is modulated at the transmission site, and the modulated signal is demodulated at the reception site.
HDMI utilizes packet data structures to transmit data over the TMDS channels. The packet data includes audio data, auxiliary data and error correction codes. These data are processed by various methods to provide a TMDS encoder.
HDMI transfers video signals, including active video data and blanking periods for horizontal and vertical synchronization signals. Digital audio and auxiliary data may be transferred during the blanking periods, but such data may be transmitted at different points. Thus, the auxiliary data is transferred at an appropriate time after it is prepared for transmission.